Current fasteners for attaching a gypsum wallboard panel (drywall) to a wooden building frame are inadequate in resisting shearing forces caused by seismic and hurricane lateral loading. For example, the use of fasteners specified by the Uniform Building Code for attaching a gypsum wallboard panel to a wooden building frame has resulted in severe and costly damage to interior building structures during hurricanes and Zone 4 earthquakes. As evidence, the shaking intensity during the 1994 Northridge Earthquake, having a Richter Magnitude of 5.6 (Moderate) and a Modified Mercalli Intensity of 8 to 9, caused more than 5 billion dollars worth of damage to single and multiple family units that had gypsum wallboard panels attached to wooden building frames by use of fasteners specified by the Uniform Building Code.
In addition, cyclic testing of gypsum wallboard panels fastened to wood panels by use of fasteners specified by the Uniform Building Code showed that the fasteners specified by the Uniform Building Code developed less than 60% of the lateral resistance required by the Uniform Building Code for Seismic Zone 4 loading.
Table 1, shown below, shows the specifications for the fasteners specified by the Uniform Building Code for attaching a 0.625 inch (⅝ inch) thick gypsum wallboard panel to a wooden building frame.
TABLE 1Type ofAxial LengthDiameter ofDiameter ofFastenerof FastenerFastener ShaftFastener HeadNo. 13 Gage1.625 inches0.092 inches0.297 inchesScrew(1⅝ inches)({fraction (19/64)} inches)Annular Ringed1.375 inches0.098 inchesNot specifiedNail(1⅜ inches)6d Cooler1.875 inches0.092 inches0.250 inchesNail(1⅞ inches)({fraction (16/64)} inches)Wallboard1.875 inches0.092 inches0.297 inchesNail(1⅞ inches)({fraction (19/64)} inches)
As a result of the poor lateral capacity of the fasteners specified by the Uniform Building Code, a need exists for a fastener for attaching a gypsum wallboard panel to a wooden building frame that provides a greater resistance in the gypsum wallboard panel to shearing forces caused by seismic and hurricane lateral loading than that which is provided by current fasteners, such as the fasteners specified in the Uniform Building Code.